In a related art Orthogonal Frequency Division Modulation (OFDM) Time Division Duplex (TDD) system, Medium Access Layer (MAC) Protocol Data Units (PDUs) may be broadly categorized as MAC Management PDUs and user data MAC PDUs. A MAC Management PDU is comprised of a payload containing previously agreed upon MAC management messages for operation of the MAC layer, and a MAC header attached in front of each payload. A Bandwidth Request PDU, which is needed for a user to dynamically request necessary bandwidth on the uplink, is a special type of MAC Management PDU having only a header (that is referred to as a Bandwidth Request Header) without any payload attached thereto. FIG. 1 shows the configuration of a related art Bandwidth Request Header.
According to the related art, a bandwidth request function is a procedure used when a mobile station informs a base station that uplink bandwidth allocation is necessary. The bandwidth request may be of an incremental type or an aggregation type. The base station that receives an incremental bandwidth request, must add bandwidth necessary matters to the currently allocated bandwidth, to accommodate the size of the requested bandwidth related to a corresponding connection (or access procedure). Alternatively, upon receiving a group type request, the base station should replace the previous bandwidth of the corresponding connection with the size of the requested bandwidth.
In addition to the above functions, the header can be used to perform other functions. Such functions are classified according to a type field at the front portion of the header, and the contents to be transferred correspond according to the type field. Basically, this is used to transfer other values when requesting bandwidth. For example, if the type field is 010, an uplink transmit power value is reported, and if the type field is 100, a downlink burst profile change is requested. A type field of 101 can be used to transfer a power saving class ID for sleep mode. As such, in addition to requesting bandwidth, the header can be used to report other information together with simultaneously requesting bandwidth.
In the related art, the request from the mobile terminal is limited to requesting uplink bandwidth. Also, allocation of a Fast-feedback channel (e.g., CQICH) that allows quick transferring of various feedback values was received only based according to an allocation from the base station. When the base station requests feedback values upon allocation of a CQICH region to the mobile terminal, a CQICH_Enhanced_allocation Information Element (IE), a CQICH-allocation IE or if data exists, a Fast-feedback allocation sub-header is used for informing. Only the mobile terminal that received a request through such IE or sub-header then calculates the requested feedback value and reports such thereof. Accordingly, reporting a most recent downlink channel state (condition) value of the mobile terminal with a request from the base station, changing into MIMO mode for channel improvement (enhancement) in a multiple antenna system, and other such procedures cannot be requested from the mobile terminal itself. Also, channel state (condition) report values that are reported at a report period (interval) that was determined in a uni-lateral (one-sided) manner without considering the mobility characteristics of the mobile terminal may become useless.